Electrically-operated sleeve valve and air conditioning system



NOW 1% A. A. MATTE-HES 3285,31

ELECTRICALLY-OPERATED SLEEVE VALVE AND AIR CONDITIQNING SYSTEM Filed on. 26, 1964,

LQF ig r?) 64 Q 3 72 5b 5Q Co BQNSER Kscenlaa MORATOK 4 4,

MvENTo ALAN A Mm'wwes aw/M ATTQRNELY United States Patent 3 285,031 ELECTRICALLY-OPEIiATED SLEEVE VALVE AND AIR CONDITIONING SYSTEM Alan Arthur Matthies, Milwaukee, Wis., assignor to Controls Company of America, Melrose Park, 11]., a corporation of Delaware Filed Oct. 26, 1964, Ser. No. 406,322 17 Claims. (Cl. 62217) This invention relates to sleeve valves and, more particularly, to a sleeve valve construction which is particularly well suited for use in an air conditioning system to control refrigerant flow from the evaporator to the compressor and also to an air conditioning system incorporating such a sleeve valve construction.

It has been recognized that certain advantage-s could be gained by providing an electrically-operable sleeve valve as compared to a sleeve valve using presently employed, conventional types of operating mechanisms such as pressure responsive operators and the like. For example, an electrical operator would increase the versatility and selectivity of control as well as achieve an overall simplification of the valve operating mechanism. However, since one of the advantages of a sleeve valve is its ability to handle relatively large capacitie in a relatively small physical size and since electrical operating mechanisms are generally physically larger than such other conventional types of operators, the use of an electrical operator in a sleeve valve and the advantages to be gained thereby have been subordinated in favor of the relatively smaller physical size control which can be achieved by using such other conventional type operating mechanisms.

An object of this invention is to provide an electricallyoperable sleeve valve while maintaining a valve of relatively small physical size.

Another object of this invention is to provide an improved electrically-operable sleeve valve which is capable of controlling the volume of flow encountered in the suction line of an air conditioning system but having a physical size which permits the sleeve valve to be positioned internally of the flow path of the air conditioning system.

A still further object of this invention is to provide a sleeve valve construction which controls an air conditioning system in accordance with the output of that system.

More general objects of this invention are to provide an improved sleeve valve of relatively small physical size which exhibits improved operating characteristics, and to provide an improved air conditioning control system incorporating such a valve.

For the achievement of these and other objects, this invention proposes a sleeve valve construction which requires minimum operating forces to open and close the valve and which further insures that these desirable low operating forces are maintained over extended operation of the valve. By achieving and maintaining low operating forces, a relatively small electrical operating mechanism can be used with the assurance that the electrical operating mechanism will be adequate to operate the valve throughout the operating life of the valve. Furthermore, the construction proposed by this invention achieves optimum dissipation of self-generated heat in the electrical operating mechanism to reduce the otherwise adverse effects of such heat on the operating mechanism and correspondingly minimize the restrictions normally placed on an electrical operating mechanism due to such self-generated heat. The improved heat dissipating characteristics contribute in reducing the size of the electrical operating mechanism which can be used in the sleeve valve.

ice

A further advantage resulting from the sleeve valve being electrically operable is that it can be controlled remotely thereby increasing the control possibilities for the valve. For example, the valve can be controlled on the basis of the output of an air conditioning system such as in accordance with evaporator fin temperature so that the valve will interrupt refrigerant flow when fin temperature falls below a predetermined value.

Other objects and advantages will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the embodiment shown in the drawings, in which:

FIG. 1 is a schematic illustration of an air conditioning system embodying this invention;

FIG. 2 is an axial section through a sleeve valve constructed in accordance with this invention; and

FIG. 3 is a section view taken generally along lines 3-3 of FIG. 2.

This invention has been illustrated and will be described in connection with an air conditioning system but it will be appreciated that the sleeve valve of this invention is not intended to be nor is it necessarily limited to use in an air conditioning system.

With particular reference to the drawings, the air conditioning system of FIG. 1 includes compressor 10, condenser 12, receiver 14, evaporator 16 and suction line 18 connecting the evaporator and compressor. As schematically illustrated in FIG. 1, sleeve valve 20 is mounted at the compressor inlet which is formed by a suitable coupling 22 and the sleeve valve is positioned within the compressor, specifically within the compressor suction annulus (not shown). As will be described more completely hereinafter, the sleeve valve is electrically operated and is controlled by temperature responsive switch 24 associated with evaporator 16 and arranged to respond to evaporator fin temperature. Switch 24 can be mounted for exposure to the fin temperature in any one of a number of suitable arrangements, e.g. by direct attachment to one of the fins, and since such arrangements are conventional and well known in the art no specific arrangement between the switch and the evaporator fin has been illustrated. Electrical lead 26 extends from coupling 22 and connects the sleeve valve to one side of switch 24 and the other side of the switch is connected through lead 28 to a suitable electrical source (not shown). In a manner to be described more completely hereinafter one side of the electrical operating mechanism of the valve is connected to lead 26 and its opposite side is connected to ground. With this arrangement the sleeve valve is positioned within the air conditioning system and not as an appendage thereto, and it controls refrigerant flow from the suction line into the compressor in response to evaporator fin temperature which is a measure of the output of the air conditioning system. It will be appreciated that switch 24, or a similar control device, could "be arranged to respond to and control the sleeve valve in accordance with other indications of air conditioner output such as the temperature of the discharge air.

With this general description of the air conditioning system and the association of the sleeve valve With that system in mind, the specific construction of sleeve valve 20 will now be described.

Sleeve valve 20 is connected at inlet opening 30 in compressor housing 10a, only a portion of the housing is illustrated in FIG. 2. The sleeve valve extends from from inlet 30 into the suction annulus chamber 10b of the compressor and the joint between the sleeve valve and the compressor housing is sealed against leakage by O-ring 33. Member 32 of the valve is connected to the compressor housing at inlet 30' in any suitable, conventional and well-known manner (not shown). Valve member 32 has an open end 36 and a hollow generally cylindrical wall 38 terminating in an end 40 closed by integral wall 42. Wall 42 includes openings 44 and 46 and inserts 48 and 50 are positioned in these openings for a purpose which will be described more completely hereinafter and also to maintain the inner end of valve. member 32 closed. Opening 36 of valve member 32 serves as the inlet to the valve from the suction line and valve ports 52 are provided through cylindrical wall 38 of member 32 so that when ports '52 are open refrigerant flows from the inlet opening through the interior passage defined by cylindrical wall 38 to the valve ports where it is discharged into the suction annulus chamber of the compressor. As can be seen from a comparison of FIGS. 2 and 3, valve ports 52 are arranged in axially aligned pairs with three such pairs being cir-cumferentially spaced around cylindrical wall 38 of valve member 32.

Valve ports 52 are selectively opened and closed by an elongated, generally hollow cylindrical sleeve 54 which is coaxially arranged with valve member 32 and includes an inner cylindrical wall 56 which telescopes over the outside of cylindrical wall 38. The sleeve is supported for axial movement relative to valve member 32 to assume either a first position, not illustrated, wherein it overlaps and closes valve ports 52 or a second position, illustrated in FIG. 2, wherein it is moved axially upward out of overlapping relationship with and opens valve ports 52. More specifically and as illustrated in the drawings, sleeve 54 contains valve ports 60 which, similar to valve ports 52, are arranged in axially aligned pairs with the pairs being circumferentially spaced around sleeve 54 and in accordance with the spacing between valve ports 52. When sleeve 54 is moved upwardly to its second position, valve ports 60 are aligned with valve ports 52 and refrigerant is free to flow from the interior of valve member 32 into the suction annulus chamber of the compressor.

The operating mechanism for moving the sleeve to open and close the valve ports preferably takes the form of a solenoid operating mechanism positioned within the sleeve and including as operating elements coil spring 61 and coil 62. Structurall coil 62 is wound on bobbin 64. One end of the bobbin is formed to provide a radially extending flange 66 positioned for engagement between lips 68 and 70 on inserts 48 and 50 and wall 42 of valve member 32. The other end ofbobbin 64 i connected to the coil in a conventional, well-known manner. Each of the inserts is also provided with second lips 72 and 74 facing oppositely from insert lips 68 and 70 and directly engaging wall 42 of valve member 32. The inner surfaces of inserts 48 and 50 are provided with threads 76 and 78. Threaded terminal post 80 is engaged between inserts 48 and 50 and as it is tightened down on the inserts it tightens the inserts against end 42 of valve member 32 and clamps flange 66 of bobbin 64 between the inserts and end 42 thereby completing the connection of the solenoid coil assembly, inserts 48 and 50 and post 80 in the sleeve valve.

The electrical connections for solenoid coil 62 are made on one side through lead 82 which is electrically connected to bobbin 64 and through the bobbin and valve member 32 to compressor housing 100 which is at ground potential. The other side of the solenoid coil is connected by lead 84 which passes through insert 48 and is suitably connected to post 80. Inserts 48 and 50 are made of suitable electrical insulating material and a layer of insulating material 86 is provided between post 80 and valve member end 42 to insulate the post from valve member 32. Post 80 is made of electrical conducting material and functions as a terminal for the solenoid coil for connection (not shown) to electrical lead 26 and through that lead to switch 24.

To complete the structure of the sleeve valve and the solenoid operating mechanism, end 87 of the sleeve is closed by a T-shape in cross section member 88 which radial shoulder 106.

includes circular portion 90 fixed to the sleeve by rolled lip 92 and an elongated portion 94 extending into the bore of the solenoid coil assembly to provide the armature for the solenoid operating assembly. Screw 96 extends through an axial opening 98 in portion 94 and is threaded into opening 100 provided in hub 102 which is integral with valve member 32 and also extends into the bore of the solenoid coil assembly. Opening 104 of increased diameter is formed in portion 94 to provide Spring 61 is seated between radial shoulder 106 and the upper end of hub 102 and biases sleeve 54 toward engagement with the head of screw 96. The screw head provides a limit on the movement of the sleeve to open the valve ports and the degree of opening of the valve ports in the valve open position can be varied, if desired, by adjusting screw 96.

In operation and with the air conditioning system functioning to accommodate a given load, the sleeve valve will assume the position illustrated in FIG. 2 with ports 52 open and supplying refrigerant to the compressor;

The thermally responsive switch will monitor the evaporator fin temperature and can be preset to energize the solenoid coil to close the valve ports if the fin temperature falls below a predetermined temperature indicating an excess of refrigerant being supplied for the particular load. More specifically, if the compressor is operating to accommodate a particular demand on the air conditioning system and that demand should fall off, the temperat-ure of the evaporator fin will decrease due to an excess of refrigerant being supplied for the load which is now on the system. If this condition were to remain the evaporator would eventually freeze up. The control system of this invention prevents this condition from occurring in that the thermally responsive switch will energize the solenoid operating mechanism of the sleeve valve at a prescribed fin temperature, which can be preselected Well above the temperature at which evaporator freeze up will occur, thereby interrupting refrigerant flow to the compressor and correspondingly to the evaporator. In operation this system will tend to modulate about a given output temperature.

- Although with valve ports 52 open the pressure drop across the valve is negligible, the interior of valve mem ber 32, the valve inlet, can be considered as the high pressure side of the valve and the suction annulus side of the valve can be considered as the low pressure side, particularly when the valve ports are closed. A low clearance, sliding fit is provided between the inner wall surfaces of sleeve 54 and the outer wall surface of valve member 32, preferably this clearance is in the range of .0005 to .0015 inch. Therefore, some leakage of the refrigerant past the ports occurs particularly when the ports are closed. The valve constructed in accordance with this invention is designed to take advantage of this leakage in that the leakage producesa film of gaseous media between the opposed surfaces of the sleeve and the fixed valve member which provides a relatively frictionless bearing between the opposed surfaces thereby attributing relatively low operating force characteristics to the valve. Moreover, with the valve elements arranged as described, namely stationary valve member 32 and movable valve member 54 being positioned on the high and low pressure sides of the valve, respectively, interaction between the movable sleeve and the film will cause the sleeve to maintain a concentric relationship with the valve member to in turn maintain the low operating force characteristics for the valve during valve operation over the useful operating life of the valve. In addition to the relatively frictionless bearing and maintaining the low operating force characteristics, the interaction between the gaseous film and the sleeve reduces any noise which normally might occur as a result of sleeve flutter and engagement with the stationary valve member in that the film provides a cushion between the sleeve and the valve member pre venting such engagement or at least keeping it to a minirn-um. It is believed that the tendency of the sleeve to maintain a concentric relationship with the stationary valve member, and the reduction of engagement between it and the stationary valve member, can be explained by the fact that the movable member being positioned. on the low pressure side of the valve acts against a higher pressure when it tends to move toward the valve ports and that movement toward the valve ports actually increases the pressure at the ports which pressure then produces a force counteracting sleeve movement to maintain the sleeve in a condition of equilibrium and positioned concentrically with the stationary valve member. With this concentric relationship the valve exhibits and maintains relatively low operating force characteristics and the solenoid coil and spring 61 can be substantially smaller in physical size and strength than would normally be required for a valve designed to handle a particular volume of flow through the valve.

Sleeve 54 is preferably provided with two exhaust ports 108 and 110 which are positioned above valve member 32 when the valve ports are closed. Ports 108 and 110 provide openings through which the gaseous media leak ing past the closed valve ports can escape from the interior of the sleeve. If the gaseous media were allowed to accumulate within the sleeve when the valve ports are closed, the pressure within the sleeve would increase producing a piston-type action on the sleeve which would eventually raise the sleeve and open the valve ports prematurely. Exhaust ports 108 and 110 prevent the occurrence of this condition and maintain the pressure within the sleeve approximately equal to that in the suction an-' nulus chamber thereby preventing any such premature opening. However, it will be appreciated that exhausting gas from within the sleeve does not adversely affect the film between the stationary and movable valve members since the gaseous media still must pass between the opposed surfaces and thereby produces the bearing film. It should also be noted that an additional advantage resulting from the structural relationship between the various elements of the sleeve valve is that, in operation, the solenoid operator assembly is positioned in the path of flow of the refrigerant, the flow path being indicated by the arrows in FIG. 2. With this arrangement refrigerant flowing through the valve passes over the sleeve and has a cooling effect on the solenoid assembly so that the solenoid can be operated at an optimum electrical input -to achieve the maximum operating force for the size of coil used. For example, a sleeve valve constructed in accordance with this invention may be approximately 2 inches in axial length and approximately to 1 inch in diameter and in that physical size a solenoid coil can be operated at 30 watts. This is possible because of the improved dissipation of self-generated heat due to the cooling effect the refrigerant has as it flows over the sleeve. For optimum heat dissipation the valve of this invention also contemplates the use of an improved solenoid construction wherein coils 112 are wound directly on bobbin 64 in a conventional manner but without the usual insulating sleeve between the bobbin and the coil. Bobbin 64 is made from a material having a relatively high heat conductivity so that the bobbin acts as a heat sink for the self-generated heat. This heat is conducted through stationary member 32 to sleeve 54 where it is dissipated to the refrigerant flowing past the sleeve.

This invention achieves an electrically operable sleeve valve while maintaining a relatively small physical size for the sleeve valve by achieving low operating force characteristics for the valve and optimum dissipation of self-generated heat. The electrically-operated valve can be positioned internally of an air conditioning system, it provides increased versatility and selectivity of control, and it simplifies the construction of the sleeve valve as compared to other control arrangements, for example a pressure responsive operating assembly. Furthermore, in certain installations and under certain conditions the electrically-operated sleeve valve affords improved operation as compared to such other actuators.

For example, in an automotive air conditioning system utilizing a pressure operated sleeve valve, it is possible to start the auto and by accelerating to high speeds close the valve before the auto interior has cooled down. More particularly, acceleration to and steady driving at high speeds has a tendency to decrease system pressure and, since pressure operated sleeve valves interrupt refrigerant flow in response to a decrease in system pressure, cause the sleeve valve to close prematurely. This premature closure of the pressure operated sleeve valve interrupts refrigerant flow and adversely affects what is commonly referred to as pull-down time, i.e. the time necessary to initially cool the auto interior to a desired temperature, by unduly increasing the pull-down time. This cannot happen with the electrically-controlled system since it can be made to function, as illustrated in FIG. 1, not on any internal system condition but on the basis of the system output. Therefore, regardless of any such abnormal conditions which may exist within the system itself, the sleeve valve will interrupt refrigerant flow only if the output of the system is in excess of that necessary to meet a particular demand.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What I claim is:

1. A solenoid-operated sleeve valve comprising, in combination,

a fixed valve member characterized by a cylindrical outer Wall portion, means defining a plurality of relatively spaced first valve ports in said outer wall portion, and means defining an inlet flow passage through said fixed valve member and communicating with said first valve ports,

a sleeve member having a cylindrical inner wall portion concentrically arranged with and disposed in telescoping relationship over the cylindrical outer wall portion of said fixed valve member, said sleeve member disposed on the outlet side of said first valve ports with said inner wall in opposed relationship with said outer wall and including means defining a plurality of second ports in and opening through Zhe cylindrical inner Wall portion of said sleeve memmeans supporting said sleeve member for an axial movement relative to said fixed valve member to move said second ports into and out of registry with said first valve ports to open and close said first valve ports,

solenoid means supported from said fixed valve member connected to said fixed valve member and said sleeve member for moving said sleeve member axially to open and close said first valve ports,

and a low clearance fit between said outer wall portion of said fixed valve member and said inner wall portion of said sleeve member so that, in operation, said opposed inner and outer wall portions are separated by a film of the medium being controlled to provide a bearing between said inner and outer wall portions and to maintain the cylindrical wall portion of said sleeve member in concentric relationship with the cylindrical wall portion of said fixed valve member to maintain a condition whereby relatively low operating forces are required to move said sleeve member during operation of said sleeve valve.

2. A solenoid-operated sleeve valve comprising, in

combination,

a first valve member characterized by a cylindrical outer wall portion, means defining a plurality of valve ports in said wall portion and means defining an inlet flow passage through the interior of said valve member and communicating with said valve ports,

a sleeve member having an inner cylindrical wall portion concentrically arranged with and disposed in telescoping relationship over said cylindrical wall portion of said valve member, with said inner and outer wall portions in opposed relationship and having a low clearance, sliding fit therebetween,

means supporting said sleeve member and said valve member for relative axial movement in opposed directions to position said sleeve member selectively in a first position overlapping and closing said valve ports and a second position out of overlapping relationship with and opening said valve ports,

means connected between and operative to provide axial movement of said sleeve member relative to said valve member in one of said directions,

and solenoid means supported on said first valve member and connected to said first valve member and said sleeve member and operative to provide movement of said sleeve member relative to said valve member in an opposite direction, the opposed cylindrical wall portions of said valve and sleeve members, in operation, by a film of the medium being controlled to provide a bearing between said opposed wall portions so that said sleeve member wall portion assumes and is maintained in concentric relationship with said valve member wall portion to thereby require relatively low operating force to produce said relative movement.

3. A sleeve valve comprising, in combination,

a fixed valve member characterized by an outer cylindrical wall portion, means defining a plurality of valve ports in said wall portion and means defining an inlet flow passage through said fixed valve memher and communicating with said valve ports,

- a sleeve member disposed exteriorly of said fixed valve member and having an inner cylindrical wall portion concentrically arranged with and disposed in telescoping relationship on said outer valve member wall portion with said inner and outer Wall portions having a low clearance fit therebetween,

means supporting said sleeve member for axial movement relative to said valve member and between a first position overlapping and closing said valve ports and a second position out of overlapping relationship with and opening said valve ports,

means connected to said sleeve member and operative to move said sleeve member to one of its first and second positions,

and electrically energized means supported on said fixed valve member and connected to said sleeve member and operative to move said sleeve to the other of its first and second positions, the cylindrical wall portions of said valve and sleeve members disposed in opposed relationship and arranged so that, in operation, said opposed wall portions are separated by a film of the medium being controlled to provide a bearing between said opposed Wall portions and so that said sleeve member wall portion is maintained in concentric relationship With said valve member wall portion to thereby require relatively low operating forces to produce said relative movement.

4. A solenoid-operated sleeve valve comprising, in combination,

a fixed valve member characterized by a cylindrical outer Wall portion, means defining a plurality of relatively spaced valve ports in said outer wall portion, and means defining an inlet flow passage through said fixed valve member and communicating with said valve ports,

an elongated sleeve member having a first portion characterized by a cylindrical inner wall portion arranged in concentric relationship with and disposed in telescoping relationship on said outer wall portion of said fixed valve member and a second portion extending axially from said first portion and beyond said fixed valve member,

means supporting said sleeve member for movement relative to said fixed valve member between a first position in overlapping relationship with and closing said valve ports and a second position out of overlapping relationship with and opening said valve ports,

a low clearance fit between said inner and outer wall portions so that in operation a film of the medium being controlled by said valve is disposed between said inner and outer wall portions,

and means biasing said sleeve member to one of its positions and solenoidmeans disposed within said second sleeve portion and operatively connected to said sleeve member for moving said sleeve member to its other position.

5. The combination of claim 4 wherein said sleeve is supported by said support means for axial movement between said first and second positions.

6. The combination of claim 5 wherein said sleeve member is in the form of a hollow, generally cylindrical member with one end telescoping over said cylindrical outer wall portion of said fixed valve member and including means closing the opposite end of said sleeve member and including a portion operatively arranged with said solenoid means for cooperation therewith to move said sleeve member to said other sleeve member position upon energization of said solenoid means.

7. The combination of claim 6 including means defining openings in said sleeve spaced outwardly of said fixed valve member when said valve ports are closed to afford a passage for media leaking past said valve ports.

8. The combination of claim 4 wherein said solenoid means includes a bobbin of heat conducting material and a cylindrical coil wound on and directly engaging said bobbin,

and including means connecting said bobbin to said sleeve and providing a heat transfer path from said bobbin to said sleeve so that said bobbin provides a heat sink for said coil and heat generated during operation of said solenoid is dissipated through said sleeve.

9. An elongated cylindrical solenoid-operated sleeve valve comprising, in combination,

a hollow cylindrical valve member having a closed end, an open end providing an inlet to said valve and including means defining valve ports through the side walls of said valve member intermediate the ends thereof,

a hollow cylindrical sleeve concentrically arranged with a portion of said valve member and having an end thereof telescoping over said closed end of said valve member with a portion on the inner wall of said sleeve arranged in opposed relationship with a portion of the outer wall of said valve member and the remainder of said sleeve extending axially beyond said closed end of said valve member, said sleeve being free to move relative to said valve member and including means in the telescoping portion thereof defining ports arranged for movement into and out of alignment with said valve ports upon axial movement of said sleeve relative to said valve member to open and close said valve ports,

solenoid means including a solenoid coil disposed Within said sleeve and extending away from said closed valve member end,

and means biasing said sleeve in one axial direction relative to said valve member and said solenoid means connected to and operative, when energized, to move said sleeve in an opposite axial direction to selectively open and close said valve ports.

10. The combination of claim 9 including means closing the opposite end of said sleeve member and arranged posed in the path of flow between and controlling flow through said suction line from said evaporator to said compressor, said sleeve valve comprising, in combination,

a fixed valve member characterized by a cylindrical outer wall portion, means defining a plurality of relatively spaced first valve ports in said outer wall portion, and means defining an inlet passage through the interior of said valve opening to flow through said suction line and communicating with said first valve ports,

a sleeve member having a cylindrical inner wall portion concentrically arranged with and disposed in telescoping relationship on the cylindrical outer wall portion of said fixed valve member, said sleeve member including means defining a plurality ofsecond valve ports in and opening through the cylindrical inner wall portion of said sleeve member,

means supporting said sleeve member for movement relative to said fixed member to move said second ports into and out of alignment with said first valve ports to open and close said first valve ports,

means including solenoid means operatively connected to said sleeve and operative to move said sleeve in one direction relative to said fixed valve member upon energization of said solenoid means and in an opposite direction upon de-energization of said solenoid means to move said second ports into and out of alignment with said first valve ports,

and temperature sensitive control means exposed to and responsive to the output of said refrigeration system and operative to actuate said solenoid means in ac cordance with the temperature of said output and move said sleeve to close said first valve ports when said output falls below a predetermined temperature.

13. In a refrigeration system including an evaporator,

a compressor and a suction line between said evaporator and compressor the improvement of a sleeve valve disposed in the path of flow between and controlling fiow through said suction line from said evaporator to said compressor, said sleeve valve comprising, in combination,

a first valve member characterized by a cylindrical wall portion, means defining a plurality of valve ports in said wall portion and means defining an inlet flow passage through said valve member opening to said suction line flow and communicating with said valve ports,

a sleeve member having a cylindrical wall portion concentrically arranged with and disposed in telescoping relationship with said cylindrical wall portion of said valve member,

means supporting said sleeve member and said valve member forrrelative movement therebetween in opposed directions to move said sleeve member between a first position overlapping and closing said valve ports and a second position out of overlapping relationship with and opening said valve ports,

means connected between and operative to provide relative movement of said sleeve member and said valve member in one of said directions,

electrically energized means connected between and operative to provide said relative movement of said sleeve member and said valve member in the opposite direction, the cylindrical wall portions of said valve and sleeve members disposed in opposed relationship and arranged so that, in operation, said opposed wall portions are separated by a film of the medium being controlled which medium provides a bearing between said opposed wall portions and said sleeve member wall portion is maintained in concentric relationship with said valve member wall portion,

and temperature sensitive control means exposed to and responsive to the output of said refrigeration system and operative to actuate said electric-ally energized means in accordance with the temperature of said output and move said sleeve to close said first valve ports when said output falls below a predetermined temperature.

14. In a refrigeration system including an evaporator,

a compressor and a suction line between said evaporator and compressor the improvement of a sleeve valve disposed in the path of flow between and controlling flow through said suction line from said evaporator to said compressor, said sleeve valve having a longitudinal axis extending in the direction of said path of flow and comprising, in combination,

:a fixed valve member characterized by a cylindrical outer wall portion, means defining a plurality of relatively spaced valve ports in said outer wall portion, and means defining an inlet flow passage through said fixed valve member opening to said suction line flow and communicating with said valve ports,

an elongated sleeve member having a first portion characterized by a cylindrical inner wall portion arranged in concentric relationship with and disposed in telescoping relationship on said outer wall portion of said fixed valve member and a second portion extending axially from said first portion and beyond said fixed valve member,

means supporting said sleeve member for movement relative to said fixed valve member between a first position in overlapping relationship with and closing said valve ports and a second position out of overlapping relationship with and opening said valve ports,

a low clearance fit between said inner and outer wall portions so that in operation a film of the medium being controlled by said valve is disposed between said inner and outer wall portions,

means biasing said sleeve member to one of its positions and solenoid means disposed within said second sleeve portion and operatively connected with said sleeve member to move said sleeve member to its other position,

and temperature sensitive control means exposed to and responsive to the output of said refrigeration system and operative to actuate said solenoid means in accordance with the temperature of said output and move said sleeve member to its second position to close said valve ports when said output exceeds a predetermined temperature.

15. The combination of claim 14 wherein said sleeve member is in the form of a hollow, generally cylindrical member with one end telescoping over said cylindrical outer wall portion of said fixed valve member, and including means closing the opposite end of said sleeve member and including a portion operatively arranged with said solenoid means for cooperation therewith to move said sleeve member to said other sleeve member position, and means defining openings in said sleeve spaced outwardly of said fixed valve member when said valve ports are closed to afford a passage for media leaking past said fixed ports.

16. The combination of claim 15 wherein said solenoid means includes a bobbin of heat conducting material and a cylindrical coil wound on and directly engaging said bobbin,

and including means connecting said bobbin to said sleeve and providing a heat transfer path from said bobbin to said sleeve so that said bobbin provides a heat sink for said coil and heat generated during operation of said solenoid is dissipated through said sleeve.

17. In a refrigeration system including an evaporator,

a compressor and a condenser the improvement of a sleeve valve disposed in the path of flow and controlling flow through said system, said sleeve valve comprising, in combination,

a first valve member disposed in said system flow characterized by a cylindrical wall port-ion, means defining a plurality of valve ports in said wall portion and means defining an inlet flow passage through said valve member Opening to said system flow and communicating with said valve ports,

a sleeve member having a cylindrical wall portion concentrically arranged with and disposed in telescoping relationship over said cylindrical Wall portion of said valve member,

means supporting said sleeve member and said valve member for relative movement therebetween in opposite directions to move said sleeve member between a first position overlapping and closing said valve ports and a second position out of overlapping relationship with and opening said valve ports,

means connected between and operative to provide relative movement of said sleeve member and said valve member in one of said directions,

electrically energized means connected between and MEYER PERLIN, Primary Examiner.

operative to provide said relative movement of said sleeve member and said valve member in the opposite direction, the cylindrical wall portions of said valve and sleeve members disposed in opposed relationship and arranged so that, in operation, said opposed wall .portions are separated by a film of the medium being controlled, which medium provides a bearing between said opposed wall portions, and said sleeve member wall portion is maintained in concentric relationship with said valve member wall portion,

and condition responsive control means exposed to and responsive to a condition of said refrigeration systcm indicative of the operational state of said refrigeration system and operative to actuate said electrically energized means in accordance with said condition and move said sleeve to close said first valve ports in response to a predetermined operational state of said system.

6/1961 Knudson 137-6*25.38 l/1964 Nelson 137-62538 X 

17. IN A REFRIGERATION SYSTEM INCLUDING AN EVAPORATOR, A COMPRESSOR AND A CONDENSER THE IMPROVEMENT OF A SLEEVE VALVE DISPOSED IN THE PATH OF FLOW AND CONTROLLING FLOW THROUGH SAID SYSTEM, SAID SLEEVE VALVE COMPRISING, IN COMBINATION, A FIRST VALVE MEMBER DISPOSED IN SAID SYSTEM FLOW CHARACTERIZED BY A CYLINDRICAL WALL PORTION, MEANS DEFINING A PLURALITY OF VALVE PORTS IN SAID WALL PORTION AND MEANS DEFINING AN INLET FLOW PASSAGE THROUGH SAID VALVE MEMBER OPENING TO SAID SYSTEM FLOW AND COMMUNICATING WITH SAID VALVE PORTS, A SLEEVE MEMBER HAVING A CYLINDRICAL WALL PORTION CONCENTRICALLY ARRANGED WITH AND DISPOSED IN TELESCOPING RELATIONSHIP OVER SAID CYLINDRICAL WALL PORTION OF SAID VALVE MEMBER, MEANS SUPPORTING SAID SLEEVE MEMBER AND SAID VALVE MEMBER FOR RELATIVE MOVEMENT THEREBETWEEN IN OPPOSITE DIRECTIONS TO MOVE SAID SLEEVE MEMBER BETWEEN A FIRST POSITION OVERLAPPING AND CLOSING SAID VALVE PORTS AND A SECOND POSITION OUT OF OVERLAPPING RELATIONSHIP WITH AND OPENING SAID VALVE PORTS, MEANS CONNECTED BETWEEN AND OPERATIVE TO PROVIDE RELATIVE MOVEMENT OF SAID SLEEVE MEMBER AND SAID VALVE MEMBER IN ONE OF SAID DIRECTIONS, ELECTRICALLY ENERGIZED MEANS CONNECTED BETWEEN AND OPERATIVE TO PROVIDE SAID RELATIVE MOVEMENT OF SAID SLEEVE MEMBER AND SAID VALVE MEMBER IN THE OPPOSITE DIRECTION, THE CYLINDRICAL WALL PORTIONS OF SAID VALVE AND SLEEVE MEMBERS DISPOSED IN OPPOSED RELATIONSHIP AND ARRANGED SO THAT, IN OPERATION, SAID OPPOSED WALL PORTIONS ARE SEPARATED BY A FILM OF THE MEDIUM BEING CONTROLLED, WHICH MEDIUM PROVIDES A BEARING BETWEEN SAID OPPOSED WALL PORTIONS, AND SAID SLEEVE MEMBER WALL PORTION IS MAINTAINTED IN CONCENTRIC RELATIONSHIP WITH SAID VALVE MEMBER WALL PORTION, AND CONDITION RESPONSIVE CONTROL MEANS EXPOSED TO AND RESPONSIVE TO A CONDITION OF SAID REFRIGERATION, SYSTEM INDICATIVE OF THE OPERATIONAL STATE OF SAID REFRIGERATION SYSTEM AND OPERATIVE TO ACTUATE SAID ELECTRICALLY ENERGIZED MEANS IN ACCORDANCE WITH SAID CONDITION AND MOVE SAID SLEEVE TO CLOSE SAID FIRST VALVE PORTS IN RESPONSE TO A PREDETERMINED OPERATIONAL STATE OF SAID SYSTEM. 